This section provides background information related to the present disclosure which is not necessarily prior art.
Structural performance, strength, and durability are important for materials used in load-carrying structures. Load-carrying structures may be used in a variety of applications, including in the transportation industries, medical industry, and construction and manufacturing industries, by way of non-limiting example. Such structures typically need to be capable of load bearing and supporting the weight of other components, structures, equipment, cargo, and the like. While metals perform well as load-carrying structures for many applications, they have a distinct disadvantage in being heavy. Thus, use of structural components formed of metals can reduce efficiency and fuel economy for vehicles, like automobiles, airplanes, and boats.
Composite materials have a resin matrix and at least one reinforcement material dispersed within the resin matrix (e.g., a plurality of fibers or particles). Fiber reinforced composite materials are lightweight and have been considered as alternative load-carrying structures and components. In recent years, a trend has been developing in the composites industry to incorporate more woven textile and knitted composites as the reinforcement material. However, the laying up of unidirectional fibers is an expensive and cumbersome procedure, one requiring specialized equipment and skilled labor.
Further, conventional composite materials have not exhibited the necessary robustness for long-term use in many applications, as they may not exhibit necessary durability and strength over time or may have limited ductility (e.g., high brittleness). Complex three-dimensional structures formed of conventional fiber-reinforced composites are usually formed of multiple pieces of the composite material. Structures formed from conventional fiber-reinforced materials thus have seams and joints that are susceptible to failure during long-term use (as they can introduce weak portions into the structure). Thus, improvements in designs of structures formed of composite materials, to provide necessary strength, durability, and toughness for various applications would be highly desirable to improve long-term durability of such lightweight structures.